\subsection*{Person}
Person table is used for representing persons and uses idperson as primary key. A person can either be of type passenger, customer or both. The attribute "ispassflag" is used to indicate the person is a passenger while "iscusflag" is used to indicate the person is a customer.

\subsection*{Booking}
A Booking is related to only one customer and it contains the id of the customer that is in charge of the booking. 

\subsection*{PassengerBooking}
PassengerBooking contains the id's of all the passengers that are part of a booking. It uses a combination of idbooking and idpassenger as primary key. This table allows the same idperson to appear twice in the same booking - both as a customer that is in charge of the booking and as a passenger.